Characterization of malignant ovarian mass on [18F]FDG PET/CT: using metabolic indices and degree of solidity.

BACKGROUND: The utility of [18F]FDG PET/CT for characterizing malignant ovarian mass has not been extensively studied. Here, we investigated various parameters that could be useful to differentiate malignant ovarian mass. METHODS: We enrolled 51 female patients (53.4±15.0 years), with 86 ovarian masses, who underwent pretreatment [18F]FDG PET/CT. Thirty six lesions were histopathologically confirmed with ovarian serous adenocarcinoma. Thirty one ovarian masses from gastric cancer and 19 masses from colorectal cancer were diagnosed by histopathological study or clinical follow-up. Ovarian masses were evaluated by size, solidity, and metabolic indices. The degree of solidity was scored from 1 to 5 according to the portion of solid and cyst. Metabolic activity was scored to be either positive (≥ liver) or negative (< liver). SUVmax (SUVovary) and the ratio of SUVmax of ovary to SUVmean of the liver (ovary/L ratio) were performed. Age, bilaterality and level of CA 125 were also compared. In statistical analysis, categorical variables were analyzed using Pearson's chi-square test, while continuous variables were evaluated either independent student's t-test or Mann-Whitney Test. Receiveroperating-characteristic analysis was used to obtain optimal cutoff values. RESULTS: Serous adenocarcinoma had significantly higher score in all metabolic indices over metastasis. However, there were no differences in all metabolic indices in ovarian metastasis. In contrast, solidity was different between metastatic mass from gastric and colorectal cancer. Ovarian metastasis from gastric cancer was significantly solid compared with that from colorectal cancer. In comparison of all three masses, solidity and all metabolic indices were significantly different. Patients with serous adenocarcinoma were older and had higher CA-125 level. Between metastases from gastric and colorectal cancer, there were no differences in age, bilaterality and CA-125. CONCLUSIONS: Metabolic indices such as SUVovary and ovary/L ratio could be useful to differentiate serous adenocarcinoma from metastasis. Furthermore, the degree of solidity could play a role in predicting the origin of metastasis.

Chitosan-Based Hydrogel Microparticles for Treatment of Carcinoma in a Rabbit VX2 Liver Tumor Model.

PURPOSE: To investigate potential of chitosan hydrogel microparticles (CHI) for treatment of VX2 carcinoma. MATERIALS AND METHODS: Two weeks after liver VX2 implantation, contrast-enhanced computerized tomographic scanning was conducted. Rabbits (n = 2) with successful tumor growth were treated with different sizes of 99mTc-labeled CHI (60-80 µm and 100-120 µm) via intra-arterial hepatic catheterization. Liver distribution of 99mTc-labeled CHI was determined by means of autoradiography, a radiation-based photographic technique. In the next part of this study, therapeutic effectiveness was examined with the use of CHI with the size range of 60-80 µm (n = 11). Tumor growth response and levels of blood liver enzymes were studied at baseline and 1 and 2 weeks after CHI treatment. RESULTS: Successful tumor growth was confirmed in all rabbits (24/24). Intrahepatic CHI with the size range of 60-80 µm resulted in liver localization in more close proximity to tumor nodule versus 100-120 µm. Baseline tumor volume was 1,909 ± 575 mm3 in animals receiving CHI versus 1,831 ± 249 mm3 in control animals (P = .342). In control animals, tumor volume markedly increased by 1,544 ± 512% at 2 weeks after sham operation versus baseline. In animals receiving CHI, tumor volume remained relatively unchanged (54 ± 6% increase; P = .007 vs control). Levels of blood aspartate transaminase (AST) and alanine transaminase (ALT) in animals receiving CHI increased 1 week after treatment (P = .032 vs control for AST; P = .000 vs control for ALT), but returned to control levels at 2 weeks. CONCLUSIONS: CHI embolization suppressed tumor growth without appreciable damages in liver function.

αv ß3 mediated tumor imaging using 99m Tc labeled NAD/monosaccharide coated ferrihydrite nanoparticles.

This study describes the synthesis of highly water-soluble, non-toxic, and biocompatible nicotinamide adenine dinucleotide (NAD)/glucosamine (=Nga1Fh) and NAD/glucosamine/gluconic acid coated ferrihydrite nanoparticles (=Nga2Fh) and their possible uses to target tumors in living animals via 99m Tc and 125 I radioisotope labeling. The structural properties were investigated using DLS, zeta potential, TEM, FT-IR, XRD, and Raman spectroscopy. The cell toxicity in CT26 cancer cells and in vivo tumor targetability in U87MG and CT26 tumor-bearing mice was further evaluated using cRGDyK-tagged and cRGDfK-tagged ferrihydrite nanoparticles. The average diameters of the resulting Nga1Fh and Nga2Fh nanoparticles were <5 to 7 and <3 nm, respectively. The Nga2Fh nanoparticles did not show cell toxicity until 0.1 mg/mL. Using gamma camera imaging, 99m Tc-cRGDfK-Nga2Fh showed the highest tumor uptake in a U87MG tumor-bearing mouse when compared with that of 99m Tc-cRGDyK-Nga2Fh and 99m Tc-Nga2Fh. The image-based tumor-to-muscle ratio by time for 99m Tc-cRGDfK-Nga2Fh was 3.8 ± 1.7, 4.2 ± 2.0, 7 ± 1.5, 13 ± 2.0, 8 ± 3.7, and 2 ± 1.6 at 5 and 30 minutes, 1, 2, 4, and 24 hours, respectively. Although further studies are needed, the NAD/monosaccharide coated ferrihydrite nanoparticles could be presented as an interesting material for a drug delivery system.

Size Control of (99m)Tc-tin Colloid Using PVP and Buffer Solution for Sentinel Lymph Node Detection.

Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a (99m)Tc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with (99m)Tc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid ((99m)Tc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid ((99m)Tc-BPTC-50) were chosen for in vitro and in vivo studies. (99m)Tc-BPTC-50 (<20 nm) was primarily located in bone marrow and was then secreted through the kidneys, and (99m)Tc-PPTC-30 (>100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of (99m)Tc-PPTC-30 decreased over time, while (99m)Tc-BPTC-50 increased. Therefore, (99m)Tc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP.

Peptide-loaded nanoparticles and radionuclide imaging for individualized treatment of myocardial ischemia.

PURPOSE: To determine whether chitosan hydrogel nanoparticles loaded with vascular endothelial growth factor (VEGF) peptides (81-91 fragments) capable of targeting the ischemic myocardium enhance angiogenesis and promote therapeutic effects and whether radionuclide image-guided dosage control is feasible. MATERIALS AND METHODS: Experimental procedures and protocols were approved by the Institutional Animal Care and Use Committee. Rats (n = 32, eight per group) were subjected to myocardial ischemia (control group) and received chitosan hydrogel nanoparticles with VEGF165 proteins (chitosan VEGF) or VEGF81-91 peptides (chitosan peptides) via apical puncture. Ischemic hearts receiving chitosan without angiogenic factors served as the chitosan control. Myocardial perfusion was examined 7 days after surgery by using technetium 99m ((99m)Tc) tetrofosmin (37 MBq) autoradiography, and changes in vascular density with immunohistochemical staining were reviewed. Kruskal-Wallis test and Bonferroni corrected Mann-Whitney U test were used for multiple comparisons. Wilcoxon signed rank test was used to compare myocardial retention of (99m)Tc chitosan. RESULTS: Thirty minutes of myocardial ischemia resulted in perfusion defects (median, 54%; interquartile range [IQR], 41%-62%). Chitosan VEGF decreased perfusion defect extent (median, 68%; IQR, 63%-73%; P = .006 vs control) and increased vascular density (median, 81 vessels per high-power field; IQR, 72-100; P = .009 vs control). Administration of chitosan peptides reduced the degree of perfusion defects (median, 66%; IQR, 62%-73%; P = .006 vs control) and increased vascular density (median, 82 vessels; IQR, 78-92; P = .006 vs control). The effects of chitosan peptides on perfusion and vascular density were comparable to those seen with chitosan VEGF proteins (P = .713 and P = .833, respectively). Chitosan radiolabeled with (99m)Tc was administered twice at reperfusion with a 1-hour interval to determine whether image-guided dosage control is feasible. The hearts initially retained 4.6% (IQR, 4.1%-5.0%) of (99m)Tc chitosan administered and 9.2% (IQR, 6.6%-12.7%; P = .068) with subsequent injection. CONCLUSION: VEGF peptides have angiogenic potential and resulted in therapeutic effectiveness. Adjunct use of single photon emission computed tomography was also demonstrated for individualized treatment of myocardial ischemia by further tailoring the therapeutic dosing. Online supplemental material is available for this article.

Serial Migration of Iatrogenic Microembolus on 18 F-FDG PET/CT Images.

ABSTRACT: A 51-year-old woman who had a history of partial nephrectomy underwent an 18 F-FDG PET/CT image for a routine health checkup. Focal intense FDG avidity without any anatomical correlation on CT was detected in the lung. On the delayed image after 20 minutes, the focal activity migrated to a more peripheral portion. An iatrogenic microembolus is a rare but crucial false-positive finding that nuclear physicians should be aware of. Our case emphasizes the importance of meticulous FDG injection and cautious interpretation. In addition, delayed PET/CT imaging through wet reading can aid in diagnosing and help prevent unnecessary investigations.

Incidentally detected follicular thyroid carcinoma mimicking parathyroid adenoma on Tc-99m MIBI scan: A case report.

RATIONALE: Primary hyperparathyroidism, though relatively prevalent among endocrine disorders, affecting 1% of the general population, often presents diagnostic challenges. Given its potential to precipitate severe complications including nephrolithiasis and fractures, timely diagnosis, and effective management are crucial. PATIENT CONCERNS: A 38-year-old woman with hypercalcemia was referred to the Department of Nuclear Medicine for a Tc-99m MIBI scan. DIAGNOSES: Tc-99m MIBI scan showed focal increased uptake in the left thyroid gland area, initially suggesting a parathyroid adenoma. Further examination using SPECT/CT revealed a nodular lesion within the left thyroid gland showing high Tc-99m MIBI uptake. INTERVENTIONS: Left thyroid lumpectomy confirmed the lesion as follicular thyroid carcinoma. On the second Tc-99m MIBI scan conducted after total thyroidectomy, a parathyroid adenoma was eventually detected in the right lower area, enabling the subsequent appropriate treatment, a right lower parathyroidectomy. OUTCOMES: Thirteen days after the parathyroidectomy, serum levels of total calcium and parathyroid hormone returned to normal. Furthermore, bone mineral density evaluated using DEXA remained within the expected range for her age even after 14 months. LESSONS: When interpreting the Tc-99m MIBI scan, it is essential to keep in mind that various tumors rich in mitochondria, such as thyroid carcinoma, could show a high uptake of Tc-99m MIBI.

The effect of mannosylation of liposome-encapsulated indocyanine green on imaging of sentinel lymph node.

The imaging of sentinel lymph nodes (SLN) has been researched for its role in assessing cancer progression and postsurgical lymphedema. Indocyanine green (ICG) is a near-infrared (NIR) optical dye that has been approved by the Food and Drug Administration. It is known that liposome-encapsulated ICG (LP-ICG) has improved stability and fluorescence signal compared with ICG. We designed mannosylated liposome-encapsulated ICG (M-LP-ICG) as an optical contrast agent for SLN. M-LP-ICG has a higher UV absorbance spectrum and fluorescence intensity than LP-ICG. The stability of M-LP-ICG measured in 50% fetal bovine serum solution by a dialysis method was better than that of LP-ICG. M-LP-ICG demonstrated a high uptake in RAW 264.7 macrophage cell because the density of mannose is high. There were differences between M-LP-ICG and glucosylated liposome-encapsulated ICG (G-LP-ICG), which are geometrical isomers. The result of an inhibition study of M-LP-ICG showed a statistically significant decrease in uptake in RAW 264.7 cells after either co-treatment or pre-treatment with D-(+)-mannose as an inhibitor. Results from an in vitro experiment demonstrated that M-LP-ICG was specifically taken up by macrophage cells through the mannose receptor on its surface. The time-series images acquired from a normal mouse model after subcutaneous injection showed that the signal from M-LP-ICG in SLN and other organs appeared early and disappeared quickly in comparison with signals from LP-ICG. Not only the sentinel but also the draining lymph nodes were observed partly in M-LP-ICG. M-LP-ICG appears to increase the specificity of uptake and retention in macrophages, making it a good candidate contrast agent for an optic imaging system for SLN and the lymphatic system.

The usefulness of F-18 FDG PET/CT-mammography for preoperative staging of breast cancer: comparison with conventional PET/CT and MR-mammography.

BACKGROUND: The objective of the study was to compare the diagnostic efficacy of an integrated Fluorine-18 fluorodeoxyglucose (F-18 FDG) PET/CT-mammography (mammo-PET/CT) with conventional torso PET/CT (supine-PET/CT) and MR-mammography for initial assessment of breast cancer patients. PATIENTS AND METHODS: Forty women (52.0 ± 12.0 years) with breast cancer who underwent supine-PET/CT, mammo-PET/CT, and MR-mammography from April 2009 to August 2009 were enrolled in the study. We compared the size of the tumour, tumour to chest wall distance, tumour to skin distance, volume of axillary fossa, and number of meta-static axillary lymph nodes between supine-PET/CT and mammo-PET/CT. Next, we assessed the difference of focality of primary breast tumour and tumour size in mammo-PET/CT and MR-mammography. Histopathologic findings served as the standard of reference. RESULTS: In the comparison between supine-PET/CT and mammo-PET/CT, significant differences were found in the tumour size (supine-PET/CT: 1.3 ± 0.6 cm, mammo-PET/CT: 1.5 ± 0.6 cm, p < 0.001), tumour to thoracic wall distance (1.8 ± 0.9 cm, 2.2 ± 2.1 cm, p < 0.001), and tumour to skin distance (1.5 ± 0.8 cm, 2.1 ± 1.4 cm, p < 0.001). The volume of axillary fossa was significantly wider in mammo-PET/CT than supine-PET/CT (21.7 ± 8.7 cm(3) vs. 23.4 ± 10.4 cm(3), p = 0.03). Mammo-PET/CT provided more correct definition of the T-stage of the primary tumour than did supine-PET/CT (72.5% vs. 67.5%). No significant difference was found in the number of metastatic axillary lymph nodes. Compared with MR-mammography, mammo-PET/CT provided more correct classification of the focality of lesion than did MR-mammography (95% vs. 90%). In the T-stage, 72.5% of cases with mammo-PET/CT and 70% of cases with MR-mammography showed correspondence with pathologic results. CONCLUSIONS: Mammo-PET/CT provided more correct definition of the T-stage and evaluation of axillary fossa may also be delineated more clearly than with supine-PET/CT. The initial assessment of mammo-PET/CT would be more useful than MR-mammography because the mammo-PET/CT indicates similar accuracy with MR-mammography for decision of T-stage of primary breast tumour and more correct than MR-mammography for defining focality of lesion.

Mesoporous silica nanoparticle pretargeting for PET imaging based on a rapid bioorthogonal reaction in a living body.

Last-minute labeling: Mesoporous silica nanoparticles (MSNs) were modified with a very short half-life fluorine-18-labeled azide radiotracer by a cycloaddition reaction after the MSNs had reached the tumor site in mice. The tumor could then be visualized successfully with positron emission tomography.

Prediction of leg-length discrepancy in pediatric femoral shaft fracture using bone SPECT/CT: A case report.

RATIONALE: Children's bones are in the process of growing in both length and width. Therefore, evaluating whether fractures affect the growth plate or not is very crucial. However, even in cases of lower limb fractures where the growth plate remains unaffected, overgrowth or shortening of the affected limb are encountered. PATIENT CONCERNS: An 11-year-old boy was admitted to the emergency department after a passenger car accident. DIAGNOSES: A comminuted fracture of the right femoral shaft was diagnosed by X-ray image. INTERVENTIONS: Closed reduction and internal fixation were performed using intramedullary titanium elastic nails. Six months after the operation, bone union was achieved and the nails were removed. OUTCOMES: Nine months after nail removal, the right leg was unexpectedly noticed 5 mm shorter than the left one. On the initial and follow-up bone single-photon emission computed tomography/computed tomography images with a 9-month interval, radioactivity of growth plate in the right proximal femur was much lower than that of the left femur, suggesting a further increasing of leg-length discrepancy (LLD) in the future. As we expected, LLD had progressively increased up to 20 mm. Epiphysiodesis was finally decided for the left distal femur. Twenty-two months after the length equalization operation, LLD decreased to 5 mm. LESSONS: This case emphasizes that quantitative analysis of growth plate activity using bone single-photon emission computed tomography/computed tomography could predict LLD and help us decide when and which limb should be operated on for pediatric patients with lower limb fractures.

Optical imaging of MMP expression and cancer progression in an inflammation-induced colon cancer model.

The purpose of this study was to use a near-infrared (NIR) fluorescent cyclic His-Try-Gly-Phe peptide to characterize and image the expressions of matrix metalloproteinases (MMPs), which are correlated with cancer promotion, in an inflammation-induced colorectal cancer (ICRC) model. We explored the relationship between the development of colon cancer and the expression of MMPs at the same colonic sites in ICRC models. To develop ICRC models, mice were administered a single intraperitoneal dose (10 mg/kg) of azoxymethane (AOM) and exposed orally to 2% dextran sodium sulfate (DSS) for one week. MMP-2 expression and ß-catenin activation in colonic lesions were characterized by immunohistochemical (IHC) staining. After being treated with inducers for some time, cancerous lesions were found to express high ß-catenin and MMP-2. The profiles of MMP expression were correlated with ß-catenin activation in the colonic lesions. c(KAHWGFTLD)NH(2) (C6) peptide was prepared by standard Fmoc peptide synthesis to target MMPs. Molecular weight of Cy5.5-C6 was 1,954.78 g/mol (calculated MW = 1955.23 g/mol). The in vitro characterization of Cy5.5-C6 showed MMP binding specificity in a cell experiment. In vivo NIRF imaging showed high accumulation of Cy5.5-C6 in tumors with associated expression of MMP-2 in colonic lesions after intravenous injection. The MMP-2 specificity of Cy5.5-C6 was confirmed by successful inhibition of probe uptake in the tumor due to the presence of excess C6 peptide. The use of Cy5.5-C6 to target MMP-2 has the potential to be developed into an effective molecular imaging agent to monitor ICRC progress.

F-18 labeling protocol of peptides based on chemically orthogonal strain-promoted cycloaddition under physiologically friendly reaction conditions.

We introduce the high-throughput synthesis of various (18)F-labeled peptide tracers by a straightforward (18)F-labeling protocol based on a chemo-orthogonal strain-promoted alkyne azide cycloaddition (SPAAC) using aza-dibenzocyclootyne-substituted peptides as precursors with (18)F-azide synthon to develop peptide based positron emission tomography (PET) molecular imaging probes. The SPAAC reaction and subsequent chemo-orthogonal purification reaction with azide resin proceeded quickly and selectively under physiologically friendly reaction conditions (i.e., toxic chemical reagents-free, aqueous medium, room temperature, and pH ≈7), and provided four (18)F-labeled tumor targetable bioactive peptides such as cyclic Arg-Gly-Asp (cRGD) peptide, bombesin (BBN), c-Met binding peptide (cMBP), and apoptosis targeting peptide (ApoPep) in high radiochemical yields as direct injectable solutions without any HPLC purification and/or formulation processes. In vitro binding assay and in vivo PET molecular imaging study using the (18)F-labeled cRGD peptide also demonstrated a successful application of our (18)F-labeling protocol.

Oligoethylene glycols as highly efficient mutifunctional promoters for nucleophilic-substitution reactions.

Herein, we report the promising use of n-oligoethylene glycols (oligoEGs) as mutifunctional promoters for nucleophilic-substitution reactions employing alkali metal salts. Among the various oligoEGs tested, pentaethylene glycol (pentaEG) had the most efficient catalytic activity. In particular, when compared with other nucleophiles examined, a fluorine nucleophile generated from CsF was significantly activated by the pentaEG promoter. We also performed various facile nucleophilic-displacement reactions, such as the halogenation, acetoxylation, thioacetoxylation, nitrilation, and azidation of various substrates with potassium halides, acetate, thioacetate, cyanide, and sodium azide, respectively, in the presence of the pentaEG promoter. All of these reactions provided their desired products in excellent yields. Furthermore, the combination of pentaEG and a tert-alcohol medium showed tremendous efficiency in the nucleophilic-displacement reactions (fluorination and methoxylation) of base-sensitive substrates with basic nucleophiles (cesium fluoride and potassium methoxide, respectively). The catalytic role of oligoEGs was examined by quantum-chemical methods. The oxygen atoms in oligoEGs were found to act as Lewis bases on the metal cations to produce the "flexible" nucleophile, whereas the two terminal hydroxy (OH) groups acted as "anchors" to orientate the nucleophile and the substrate into an ideal configuration for the reaction.

The effect of fluorination of zinc oxide nanoparticles on evaluation of their biodistribution after oral administration.

Monitoring of the behavior of metal nanoparticles in the body following exposure is very important for investigation of the physiological fates and safety of these nanoparticles. In this study, we investigated the behavior and accumulation of nano-scaled ZnO (20 nm) and submicro-scaled ZnO (100 nm) particles in organic tissues after oral administration using PET imaging. Both types of ZnO nanoparticle (20 or 100 nm) were labeled with the radionuclide (18)F in high yield via 'click reaction'. (18)F labeling on the ZnO nanoparticles was maintained stably in simulated gastric fluid (pH 1.2) for 7 h. PET images indicated that (18)F and (18)F-ethoxy azide showed radioactivity in the bone and bladder 3 h after oral administration, whereas radioactivity for (18)F-labeled ZnO nanoparticles was seen only in the gastrointestinal (GI) tract. At 5 h post-administration, biodistribution studies demonstrate that (18)F accumulated in the bone (10.19 ± 1.1%ID g(-1)) and (18)F-ethoxy azide showed radioactivity in the bone (7.55 ± 0.6%ID g(-1)), liver, and brain (0.94 ± 0.3%ID g(-1)). Unlike (18)F and (18)F-ethoxy azide, (18)F-labeled ZnO nanoparticles showed radioactivity in the lung, liver and kidney including the GI tract. Submicro-scaled (18)F-labeled ZnO nanoparticles (100 nm) showed stronger radioactivity in the liver and kidney compared to nano-scaled (18)F-labeled ZnO nanoparticles (20 nm). In conclusion, PET imaging has the potential to monitor and evaluate the behavior of ZnO nanoparticles absorbed in organic tissues following oral exposures.

Usefulness of F-18 FDG PET/CT in subcutaneous panniculitis-like T cell lymphoma: disease extent and treatment response evaluation.

BACKGROUND.: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cutaneous lymphomas, accounting for less than 1% of cases of non-Hodgkin's lymphoma. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron-emission tomography/computed tomography (PET/CT) findings of SPTCL before and after treatment were rarely reported. CASE REPORT.: We report a case of SPTCL in which F-18 FDG PET/CT showed increased FDG accumulations in numerous subcutaneous nodules without extracutaneous disease. Contrast-enhanced CT during F-18 FDG PET/CT showed multiple minimally enhancing nodules with an infiltrative pattern in the subcutaneous layer throughout the body. Follow-up F-18 FDG PET/CT after three cycles of CHOP chemotherapy showed a complete metabolic remission of the lesions. CONCLUSIONS.: F-18 FDG PET/CT is suggested to be useful in assessing the disease activity, extent and treatment response in SPTCL.

Clinical and metabolic parameters for predicting disease progression of gallbladder adenocarcinoma.

OBJECTIVE: This study aimed to identify reliable predictors of disease progression in patients with gallbladder (GB) adenocarcinoma. PATIENTS AND METHODS: A total of 54 patients with GB adenocarcinoma underwent preoperative F-18 fluorodeoxyglucose (FDG) PET/CT. Age, sex, clinical stage, and pathologic differentiation were collected. Tumor size and PET parameters such as SUVmax, SUVmean, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis were measured. Univariate and multivariate logistic regression analyses were performed to determine the utility of clinical values and PET parameters. Pearson bivariate correlation was used to evaluate the association between progression-free survival (PFS) and various parameters. RESULTS: No recurrence was found in 15 of 54 patients, while six showed recurrence and another 33 manifested disease progression. There were significant differences in size, stage, pathologic differentiation, and PET parameters between the groups with and without recurrence/progression. However, there was no difference in those parameters between the groups with recurrence and progression. The average PFS of the groups with no recurrence, recurrence, and progression groups was 33.1, 17.1, and 5.0 months, respectively. In univariate analysis, age, sex, clinical stage, pathologic differentiation, size, and PET parameters were correlated with PFS. In multivariate analysis, only clinical stage and MTV were statistically significant and MTV showed the highest odds ratio. Pearson correlation coefficients showed moderate negative correlations between PFS and clinical stage or MTV. CONCLUSION: In GB adenocarcinoma, clinical stage and MTV are the most powerful parameters for predicting recurrence and disease progression. Based on clinical stage, MTV will represent a strong prognostic predictor.

Incidental accumulation of Technetium-99m pertechnetate in subacute cerebral infarction: A case report.

BACKGROUND: When interpreting nuclear medicine images, unexpected findings are sometimes encountered. Recognizing these findings and determining the mechanism of their occurrence could have a significant impact on early diagnosis of critical diseases and the appropriate management of patients. CASE SUMMARY: A 59-year-old man was admitted to the emergency room due to left hemiparesis, left hemifacial palsy, and mild dysarthria. After 2 wk of hospitalization, the patient complained of dry eyes and mouth. Thus, salivary scintigraphy was performed to evaluate the functional status of his salivary glands. Incidental accumulation in the right frontoparietal area was found on salivary scintigraphy. Fluid-attenuated inversion recovery phase magnetic resonance (FLAIR phase MR) image showed diffuse high signal intensity in the same area. Anterior and posterior horns of the right lateral ventricle were obliterated and the midline was slightly shifted to the left side due to right frontoparietal swelling. On salivary scintigraphy, Tc-99m pertechnetate was incidentally accumulated in a subacute cerebral infarction lesion. Two years after the diagnosis of acute infarction, the second series of salivary scintigraphy showed no abnormal activity in the brain. FLAIR phase MR image also demonstrated markedly decreased high signal intensity in the previous infarction lesion without evidence of swelling indicating chronic cerebral infarction. CONCLUSION: This case highlights that Tc-99m pertechnetate could accumulate in a subacute cerebral infarction lesion. The mechanism of an unexpected uptake of Tc-99m pertechnetate in unusual sites should be evaluated and kept in mind for better interpretation.

Iodine 125-labeled mesenchymal-epithelial transition factor binding peptide-click-cRGDyk heterodimer for glioma imaging.

In our previous study, mesenchymal-epithelial transition factor (c-Met)-binding peptides (cMBP) had been readily radiolabeled with radioactive iodide for glioma imaging because of five histidine amino acids. However, iodinated cMBP showed relatively unfavorable in vivo kinetics. For this reason, we tried to design dual peptide ligands that would be advantageous in recognizing both c-Met receptor and integrin α(v) ß(3) . A cMBP-click-cRGDyk (cyclic Arg-Gly-Asp-Tyr-Lys) heterodimer was synthesized from mini polyethylene glycol-conjugated cMBP-3 glycine (GGG)-a single name of amino acids (SC) (Ser-Cys) and cRGDyk through a click (1 + 3 cycloaddition), and then labeled with iodine 125 (I-125) via histidine in the cMBP and tyrosine in the cRGDyk. The receptor-binding characteristics and tumor-targeting efficacy of cMBP-click-cRGDyk were tested in vitro and in vivo. A cMBP-click-cRGDyk had comparable integrin α(v) ß(3) -binding affinity with cRGDyk. The results of the biodistribution of (125) I-cMBP-click-cRGDyk at 4 h showed higher tumor-to-blood, tumor-to-liver, and tumor-to-muscle ratios: 10.07, 6.76, and 11.12, compared to 2.34, 1.99, and 5.18 of (125) I-cMBP-GGG-SC, respectively. U87MG tumor xenografts could be visualized by single photon emission computed tomography (SPECT)/CT using (125) I-cMBP-click-cRGDyk and also image contrast and overall quality were improved compared to (125) I-cMBP-GGG-SC. As the results of in vivo inhibition using free cRGDyk or cMBP-GGG-SC indicated, the tumoral uptake of (125) I-cMBP-click-cRGDyk decreased. This finding means that (125) I-cMBP-click-cRGDyk was specifically uptaken by integrin α(v) ß(3) and the c-Met receptor. Although imaging quality was improved, additional experiments are needed to acquire significant image-quality improvement.

Oleyl-chitosan nanoparticles based on a dual probe for optical/MR imaging in vivo.

Oleic acid-conjugated chitosan (oleyl-chitosan) is a powerful platform for encapsulating oleic acid-decorated iron oxide nanoparticles (ION), resulting in a good magnetic resonance imaging (MRI) probe. Oleyl-chitosan could self-assemble into core-shell structures in aqueous solution and provide the effective core compartment for loading ION. ION-loaded oleyl-chitosan nanoparticles showed good enhanced MRI sensitivity in a MR scanner. Cy5.5 dye was accessed to the oleyl-chitosan conjugate for near-infrared (NIR) in vivo optical imaging. After intravenous injection of ION-loaded Cy5.5-conjugated oleyl-chitosan (ION-Cy5.5-oleyl-chitosan) nanoparticles in tumor-bearing mice, both NIRF and MR imaging showed the detectable signal intensity and enhancement in tumor tissues via enhanced permeability and retention (EPR) effect. Tumor accumulation of the nanoparticles was confirmed through ex vivo fluorescence images and Prussian blue staining images in tumor tissues. It is concluded that ION-Cy5.5-oleyl-chitosan nanoparticle is highly an effective imaging probe for detecting tumor in vivo.